Biology 067 -Final Review of Sections 1 to 9: Molecules of life, Cell structure and function, tissues,

digestion, urinary system, cardiovascular system, blood, Defence against disease.

Sectn 1: Molecules of Life

Atoms to Molecules

A covalent bond = electrons are shared between 2 atoms

An ionic bond = an attraction of charged atoms

Water and living things

Hydrogen bond = the attraction of a slightly positive covalently bonded H to a slightly negative

atom in the vicinity (usually oxygen)

Macromolecules

Macromolecules are made by joining smaller molecules (monomers) together to form longer

chains called polymers – this is done through a reaction called dehydration synthesis.

Hydrolysis is the reverse, it breaks down the polymers back into subunits.

Carbohydrates

Subunit of carbohydrate = monosaccharide

All carbohydrates are composed of C,H, and O

Monosaccharide’s dehydration reaction form polysaccharides

Starch is a type of carbohydrate

Lipids

Subunits of lipids = glycerol and 3 fatty acids

a specialized lipid is a phospholipids =glycerol, phosphate, 2 fatty acids –the phosphate group

replaces one of the fatty acids

Proteins

The subunit of a protein=amino acid

aa always have an amino group (NH2) and an acidic group (COOH)

Amino acids form a polypeptide thru dehydration rxn

aa joined by a peptide bond

H

The 4 levels of protein structure: primary, secondary, tertiary, quaternary

Level Shape Bonding

Primary Linear chain of aa Peptide bonds between aa

Secondary Helix (coiling) Pleated sheet (folding)

Hydrogen bonds between aa

Tertiary globular Final 3D shape and function: Ionic, covalent, hydrogen bonds btwn R groups

Quaternary (rare) All shapes All bonding – 2 or more associated polpeptides

Denaturation = changing the 3 dimensional shape of proteins – often caused by extremes in

heat or pH

Nucleic Acids

Nucleic acids are DNA and RNA

Subunit of nucleic acids =nucleotides

nucleotide =phosphate group, sugar, nitrogen base

ATP is a specialized nucleotide

ATP = nucleotide that carries energy in a high-energy phosphate bond – when that bond breaks,

energy is released

ATP = adenosine + 3 phosphate groups (adenosine=adenine + ribose a sugar)

Section 2: Cell structure and Function

Know function of various cell organelles – on diagram in text or in notes

Plasma membrane

The plasma membrane:

boundary between cell and its environment

determine which substances enter and leave a cell

contains receptor sites which determine how cell interacts with its environment

has proteins embedded in the plasma membrane

plasma membrane has:

hydrophilic heads face outside (and inside) the cell

hydrophobic tails face interior of membrane

Means of transport across the plasma membrane

Passive:

diffusion = movement of molecules from area of hi concentration to area of low concentration

osmosis - movement of water molecules from area of hi concentration to area of lower

concentration

facilitated transport - requires a concentration gradient and a protein carrier

Active

active transport – requires a carrier and energy

endocytosis occurs when a vesicle is formed (Stuff coming in)– the cell membrane invaginates

and engulfs something –transporting a large molecule inside via a vesicle

Exocytosis – transporting a large molecule to outside via a vesicle (stuff going out).

Nucleus and endomembrane system

after processing and modifying proteins and synthesizing phospholipids - ER forms vesicles to

transport proteins (from RER) and phospholipids (from smooth ER) to other parts of the cell

including the golgi

both SER and RER form vesicles

the golgi apparatus = packaging centre to get cell products ready for export

The lysosome = a vesicle with digestive enzymes for intracellular digestion

Mitochondria and cell metabolism

Mitochondria =primary source of ATP

Cell respiration in mitochondria (aerobic)

Section 3: Tissues There are 4 types of tissue:

1. Connective: binds structures together - provides structural support

2. Muscle: moves body and its parts

3. Nervous tissue -specialized for conduction of impulses

4. Epithelial: covers body surfaces and lines cavities

1. Connective tissue = a.Fibrous, b.Supportive, c.Fluid

3 major components of all connective tissue = cells, ground substance, protein fibers

a. Fibrous (=Loose, adipose and dense)

1.Loose –supports epithelium and lines organs

2.Adipose – specialized loose – stores fat for energy, protection and insulation

3.Dense: tendons – connect muscle to bone

Ligaments – connect bone to bone at joints

b.Supportive (= cartilage and bone)

Cartilage: solid but flexible 3 types

1.Hyaline cartilage- found at end of long bones, nose, ribs, and respiratory passages

(trachea)

2. Elastic cartilage – more flexible – i.e outer ear

3.Fibrocartilage – can withstand great pressure and tension – found between vertebra

and cushions in the knee joint

Bone

1. Compact bone – rigid CT –shafts of long bone

2. Spongy bone – ends of long bones and surrounding the bone marrow cavity – contains

red bone marrow where red blood cell are produced

c. Fluid (=blood and lymph)

1.Blood – has a fluid matrix –

o transports oxygen and nutrients to cells,

o removes CO2 and wastes from cells,

o distributes heat, and

o protects against disease.

2.lymph –tissue fluid with WBC

o Absorbs fat molecules, excess tissue fluid and solutes

o WBC engulf pathogens

2. Muscle tissue

Skeletal Smooth Cardiac

Location Muscles attached to skeleton

Around tubes (viscera and blood vessels)

heart

Function Movement of body parts

Moves “stuff” thru tubes

Heart beat pumps blood thru body

Appearance Striated Spindle shaped Branching and interconnecting

Nervous control Voluntary Involuntary involuntary

3. Nervous tissue Made up of neurons and neuroglia

Neurons have 3 parts:

1. Dendrites –receives input

2. Cell body –organelles, cytoplasm and nucleus

3. Axon – sends nerve impulses

4. Epithelial tissue

1. Simple epithelial: single layer - lining of organs - aids in absorption, protects, allows

exchange

2. Stratified epithelial: layers of cells – outer layers – protection

3. Glandular epithelium– exocrine gland (contain ducts)and endocrine glands (ductless)

secretes a product – can be single celled or as a gland

Body cavities, membranes

Cavities of the body: Dorsal (back) and ventral (front) cavities

Dorsal cavity has 2 parts: cranial and vertebral cavities

Ventral cavity into 3: thoracic, abdominal and pelvic

4 types of membranes

1. Mucous – lines the external openings of body, and in digestive, urinary and reproductive

systems

2. Serous – lines the thoracic and abdominal cavities

1) Pleura – lines thoracic cavity and covers lungs

2) Pericardium – covers heart

3) Peritoneum – lines abdominal cavity

3. Synovial –lines cavities of joints

4. Meninges –surrounds the brain and spinal cord

Section 4: Digestive system (sectn 5 macromolecules lumped in earlier)

Path of food: mouth> pharynx> esophagus> stomach> small intestine > large intestine > rectum > anus

2 types of digestion

1. Mechanical –chew and mixing food –mouth and churning of food in stomach

2. Chemical – enzyme breaks down macromolecules into subunit molecules

Functions of Parts of the digestive tract:

Mouth - mixes food with saliva, forms chewed food into a bolus for swallowing

Pharynx – back of throat – at base of pharynx you have epiglottis which is a flap that covers

trachea which stops food from going down the trachea and into lungs

Esophagus – no digestion or absorption –uses peristalsis to move food down to stomach –

rhythmic contractions of the digestive tract

-has sphincter – which is muscles that encircle a tube – between esophagus and stomach – acts

like a door

Stomach – primary functions are = store food, churn it up and begin digestion – churns food

into “stomach soup” called chyme which is very acidic – mucus protects stomach wall

- pepsin –which begins digestion of protein gastric glands in stomach make gastric juice which

has pepsin, and

- HCL which kills bacteria, breaks down connective tissue, and activates pepsin

Small intestine –main nutrient absorption, has a neutral pH,

-Duodenum – 1st 25 cm of SI – receives thru ducts:

-bile from liver and gall bladder - emulsifies fat

-Pancreatic juice from pancreas – neutralizes chyme and has enzymes

Large intestine – mainly Absorbs water, but also absorbs salts, vitamins, stores and gets rid of

indigestible

Regions: cecum, colon, rectum

Parts of the colon: ascending, transverse, descending and sigmoid

Digestive enzymes and the breakdown of starch, proteins, nucleic acids and lipids

Macro molecule

Enzyme Breakdown products

Enzyme (SI) Breakdown products

Carbo hydrates

Salivary amylase (mouth)

Maltose Maltase glucose

Pancreatic amylase (SI)

Maltose Maltase glucose

Protein Pepsin (stomach) Peptide Peptidase Amino acids

Trypsin (SI) Peptide Peptidase Amino acids

Nucleic acids Nuclease (SI) Nucleotides nucleosidase 5 C sugar + phosphate + nitrogen base

Lipid Enzyme title n/a Bile emulsifies the

fat (SI)

Lipid droplets lipase Glycerol + fatty acids

Accessory Organs

A. Pancreas

- secretes hormones functions as endocrine gland –– keeps blood glucose levels normal

Endocrine= ductless – secretes into the bloodstream directly

- secretes pancreatic juice via a duct to the small intestine –acts as exocrine gland –

Pancreatic juice contains sodium bicarbonate (neutralizes chyme) and digestive enzymes: pancreatic

amylase to digest starch/trypsin digests proteins/ lipase digests fats (after emulsification by bile)

B. Liver – largest organ,

1. monitor blood –keeps blood contents constant – removes poison, detoxifies blood.

2. Removes and stores iron, vitamin ADEK

3. Makes plasma proteins from AA

4. Maintains blood glucose

If Excess glucose in blood in hepatic veinstored in liver as glycogenbroken down as

neededagain...excess glucose in blood in hepatic vein etc...

If glycogen stored in liver is depleted, liver converts glycerol (from fat) and AA to glucose

5. Produces urea after breaking down aa

6. Produces bile – stored in gall bladder used to emulsify fat – breaks fat into tinier fat droplets,

increases surface area for lipase activity

7. Makes lipids from fatty acids helps regulate the quantity of cholesterol in blood.

C. Gall bladder

Attached to surface of liver

Stores excess bile produced by liver

Bile leaves gall bladder and moves to duodenum by common bile duct

Section 6: The Urinary System

Organs of the Urinary system

Kidneys

Ureters -Connects kidneys to bladder

Bladder -Stores urine until it is expelled

Urethra Small tube that connects bladder to exterior of body

3 main Functions of the Urinary system:

Excretion of metabolic waste: urea, uric acid, creatinine, ammonium

o Urea – end product of amino acid breakdown otherwise known as protein breakdown -

occurs in the liver

o Uric acid – formed from breakdown of nucleotides

o Creatinine – nitrogen waste formed from the end product of creatine phosphate

breakdown (which is a hi energy reserve molecule in skeletal muscles)

o Ammonium –produced as a less toxic form of ammonia

Maintenance of salt/water balance

o Regulates blood pressure by regulating blood volume

o Maintains the level of other ions in the blood

Maintenance of acid-base (pH) balance

o pH of blood ~7.4 -kidney monitors blood pH and regulates it by excreting H+ (acid) and

reabsorbing HCO3- (base) as needed

Urinary system also contributes to hormonal function Secretes erythropoietin (hormone) to increase

RBC production if O2 carrying capacity of blood decreases

o Secretes renin, an enzyme that stimulates the release of hormones to regulate the salt/water

balance of blood

Kidney structure Microscopic Structure

Blood supply:

Renal artery afferent arteriole glomerulus (knot of capillaries) efferent arteriole

peritubular capillary network venule renal vein

Parts of the nephron:

Glomerular capsuleproximal convoluted tubuleloop of nephrondistal convoluted

tubulecollecting ducts (in renal medulla -not part of nephron)

Urine Formation

Three steps or processes...

1) Glomerular filtration – in glomerular capsule

o Renal artery enters kidney -afferent arterioles branch off the renal artery –you have millions of

these afferent arterioles going off to their nephrons...

o Whole blood enters glomerulus through the afferent arteriole

o Due to increases blood pressure, H2O and small molecules move to inside of glomerular capsule

– these small molecules = glomerular filtratate the rest of the blood and its contents stay in the

blood stream

o Glomerular filtrate = water, nitrogenous waste, nutrients, salts

2) Tubular reabsorption: in proximal and distal convoluted tubule but mostly proximal convoluted

tubule

Molecules and ions are passively and actively reabsorbed from nephron back to blood in

peritubular capillary network

o Reabsorption from nephron to blood

o When Na+ ions -actively reabsorbed, chloride ions passively follow

o Reabsorption of salt increases osmolarity of blood compared to filtrate -so H2O moves

passively from tubule to blood

o Glucose and aa also reabsorbed from proximal convoluted tubule to blood –glucose should

not be in urine – if it is, possible sign of diabetes.

o What goes back into the blood: most of the water, nutrients, required salts as well as glucose

and aa

3) Tubular secretion –occurs along the length of kidney’s convoluted tubules but mostly in distal

convoluted tubule

o Second way that substances are removed from the blood and actively added to tubular fluid. -

1st way is glomerular filtration

o i.e. Hydrogen ions (H+), creatinine, and excess drugs such as penicillin -examples of some of the

substances moved by active transport from blood into the convoluted tubules.

Section 7: Cardiovascular system: heart and blood vessels

Blood vessels:

3 Types of blood vessels:

1. Arteries, arterioles -away from heart, O2 rich (except pulmonary)

2. Capillaries – gas and nutrient/waste exchange

3. Veins, venuoles – to the heart, O2 poor (except pulmonary)

Summary table:

artery capillary vein

Blood pressure Hi Low lowest Valves present or absent

Absent Absent Present

Wall thickness 3 layer 1 cell 3 layer function Take blood away from

heart Exchange of O2/CO2, nutrients/waste

Take blood to heart

arteries -oxygenated blood except: pulmonary artery

veins -deoxygenated blood except: pulmonary veins

capillaries: Arterial end, BP>OP/ midway BP=OP / venous end BP<OP

Mechanisms that aid with venous blood flow:

1. Skeletal muscle contraction

2. Pressure changes in the thorax due to respiratory movements

3. One way valves in veins

Heart Valves:

heart valves: prevent backflow

Btwn rt atrium - rt ventricle: tricuspid valve

Btwn lft atrium - lft ventricle: mitral valve (bicuspid)

rt ventricle- pulmonary trunk: pulmonary semi-lunar valve

lft ventricle -aorta: aortic semi-lunar valve

String like structures that anchor AV valve: chordae tendineae

**review order of passage of blood thru heart (diagram)

Control of the heartbeat:

The 2 sides of the heart are separated by: the septum

Systole: working phase –includes the contraction of the atrium and ventricles

Diastole: relaxation phase

Both systolic and diastolic pressure decrease with distance from left ventricle

Intrinsic (internal) control of HB:

1. Electric impulse starts in the SA node found in upper rt wall of atria

2. Both atria contract

3. Impulse then travels to AV node at base of rt atrium

4. Impulse travels down AV bundle to Purkinje fibres - ventricles contract from the

bottom up

Extrinsic control:

cardiac control centre of brain (medulla oblongata)– can cause HB to increase for flight or

fight, or decrease for normal resting

Cardiovascular pathways

1. Pulmonary circuit:

2. Systemic circuit

System that begins at intestine and flows through liver and monitors blood= hepatic portal

system

Section 8: Cardiovascular system: Blood

Functions of the blood:

1. Transport

2. Defence

3. Regulation

Composition of blood:

1. Formed elements= RBC, WBC, Platelets

2. Plasma = is composed of: water, hormones, gases (CO2 and O2), ions, vitamins, nutrients,

wastes, plasma proteins

RBC:

Transport O2 and CO2 (CO2 some of the time)

Small, biconcave and have no nucleus

Hemoglobin in RBC carries O2

Hemoglobin that carries excess H+ ions (on its way back to lungs to collect more oxygen)called

reduced hemoglobin

WBC:

Can leave bloodstream to get to area needed

5 different types of WBC and their function:

Type Function

neutrophil 1st responders, phagocytotic rxn Basophil Allergic rxn response Eosinophil Parasitic worm infection Monocyte Phagocytotic lymphocyte B cell: antibodies against bacteria antigens

T cells: cytotoxic T cells against viruses and cancer

Some defntns to remember:

Pathogens = microscopic infectious agents such as bacteria and viruses which are capable of

causing diseases = any foreign substance that stimulates the immune system

Antigen = molecules found on invading pathogens that allow them to be recognized

Platelets:

Needed for blood clotting along with clotting proteins – clump at puncture site

Section 9: Lymphatic system and immunity:

Lymphatic organs:

1. Red bone marrow - active Red bone marrow in an adult is located: skull, sternum, ribs, pelvic

bones, end of long bones.

2. Thymus

3. Spleen

4. Lymph nodes

5. Tonsils

6. Peyers patches – in small intestine

7. Appendix

Immune barriers to entry:

1. Skin

2. Oil glands – secrete chemical to kill bacteria on skin

3. Cilia – in upper respiratory tract

4. Mucous – in upper respiratory tract

5. Local area bacteria in intestine

6. Acidic ph - in stomach acid – kills bacteria

Non specific defences:

1. Barriers to entry: skin, mucous, oil, stomach acid

2. Inflammatory reaction –allows phagocytotic cells to enter tissue fluid to attack pathogens

3. complement proteins =complement system also called =Protective proteins

Complement kill foreign microbes by: causing them to burst

4. Phagocytes and natural killer cells – neutrophils and monocytes (macrophages) engulf and

destroy pathogens. NK (natural killer cells) cells release perforin and inject granzymes (similar

to how cytotoxic T cells kill pathogens) into pathogen

Specific defences:

Effective against a particular infectious agent

Immune system distinguishes self from nonself

B cells:

B lymphocytes develop in the bone marrow

Represent a specific response

Are part of an antibody-mediated immunity

Protein released by B cells= antibodies

Antibodies are proteins released from plasma cells (B cells) to fight infections

Unlike T cells, B cells DO NOT require antigen-presenting cell

T cells

Lymphocytes travel to the thymus to become mature T lymphocytes

T cells recognize antigens because they are activated by antigen presenting cells

Cytotoxic T cells produce perforin to punch holes in invading pathogen

Apoptosis =programmed cell death (PCD) once the threat of infection passes – development of

new plasma cells stop and those present undergo apoptosis because they are no longer needed

Comparison of specific immune responses between B cell and T cell immunity:

B cell T cell

Where produced Red bone marrow Red bone marrow Where mature Red bone marrow Thymus Type of mediated response Antibody mediated response Cell mediated response Antigen recognition mechanism

B cell receptor recognizes nonself

Antigen presenting cells

response -Clonal expansion to form plasma cells to produce antibodies -Memory B cells

-Cytotoxic T cells -helper T cells to help B cells -memory T cells

Acquired immunity:

Active

Long lasting

Either produced by own body or induced by vaccines Passive

Temporary

Individual given prepared antibiotics

Antibodies in mother’s milk = example of passive immunity